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I made a GSM Signal Meter and Antenna Tester which was sponsored by PCBWAY. I used nextion hmi, sim7600e gsm module and stm32f103c8t6 (with arduino bootloader).
Arduino & Nextion Codes below link:
Using Sim808 with arduino Tutorial:
Tweets by teknikkariyer
Eğitim Gönül İşidir.
source by Teknik Kariyer